class Person:
    pass


class Worker(Person):
    pass


class Student(Person):
    pass


class Teacher(Person):
    pass


class Factory:
    def get_person(self, p_type):
        if p_type == 'w':
            return Worker()
        elif p_type == 's':
            return Student()
        else:
            return Teacher()


pf = Factory();
worker = pf.get_person("w")
student = pf.get_person("s")
teacher = pf.get_person("t")
print(teacher)